CAJ | 학술논문

　　在不同焊接速度下对11 mm 厚的2A70-T6铝合金进行搅拌摩擦焊，并对焊缝进行显微组织观察和力学特性测试。结果表明：采用旋转速度为300 r/min、焊接速度为220 mm/min进行焊接时，可获得优质的焊缝接头，其焊缝抗拉强度为357.6 MPa；前进侧的熔合过渡区焊缝金属变化剧烈；焊核区呈现细小的等轴状晶粒；返回侧熔合过渡区塑性金属变形的梯度较前进侧缓和。随着焊接速度的增大，焊核区和晶粒尺寸逐渐变小，焊缝的抗拉强度也逐渐增大，但增大幅度逐渐变小。
　　재불동한접속도하대11 mm 후적2A70-T6려합금진행교반마찰한，병대한봉진행현미조직관찰화역학특성측시。결과표명：채용선전속도위300 r/min、한접속도위220 mm/min진행한접시，가획득우질적한봉접두，기한봉항랍강도위357.6 MPa；전진측적용합과도구한봉금속변화극렬；한핵구정현세소적등축상정립；반회측용합과도구소성금속변형적제도교전진측완화。수착한접속도적증대，한핵구화정립척촌축점변소，한봉적항랍강도야축점증대，단증대폭도축점변소。
Friction stir welding of 2A70?T6 aluminum alloy with the thickness of 11 mm was carried out under different welding speed,the microstructure of weld was observed and the joint strength was tested. The results show that high quality joint can be obtained at the rotating speed of 300 r/min and welding speed of 220 mm/min,and the joint strength is 357.6 MPa. The transition zone metal at the advancing side of the weld changes dramatically,and the microstructure in the nugget zone is equiaxed fine grain,the transition zone metal at the retreating side of the weld changes smoothly compared with that at the advancing side. With the welding speed increasing,the weld nugget zone and the grain size gradually decrease,and the joint strength increases,but the increasing amplitude decreases.